From 313c9b12d95c3213c28d01468efefa7a225d166c Mon Sep 17 00:00:00 2001
From: yogi <yogiqhz@gmail.com>
Date: Sun, 15 Dec 2024 23:45:20 -0300
Subject: [PATCH 1/2] =?UTF-8?q?Corre=C3=A7=C3=A3o:=20ordem=20dos=20loops?=
 =?UTF-8?q?=20de=20h()=20deve=20ser=20reversa=20(assim=20como=20estava=20n?=
 =?UTF-8?q?o=20commit=20anterior)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 Strings/slides/hashes/codes/double_hash.cpp | 3 ++-
 Strings/slides/hashes/codes/h.cpp           | 3 ++-
 Strings/slides/hashes/codes/subs.cpp        | 5 +++--
 3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/Strings/slides/hashes/codes/double_hash.cpp b/Strings/slides/hashes/codes/double_hash.cpp
index 676d4ee8..5ea2fbf3 100644
--- a/Strings/slides/hashes/codes/double_hash.cpp
+++ b/Strings/slides/hashes/codes/double_hash.cpp
@@ -6,9 +6,10 @@ int f(char c) { return c - 'a' + 1; }
 
 int hi(long long pi, long long qi, const string& s)
 {
+    int N = s.size();
     long long ans = 0;
 
-    for (auto c : s)
+    for (int i = N - 1; i >= 0; --i)
     {
         ans = (ans * pi) % qi;
         ans = (ans + f(c)) % qi;
diff --git a/Strings/slides/hashes/codes/h.cpp b/Strings/slides/hashes/codes/h.cpp
index 7f3b1e5c..4fec5960 100644
--- a/Strings/slides/hashes/codes/h.cpp
+++ b/Strings/slides/hashes/codes/h.cpp
@@ -5,9 +5,10 @@ int f(char c)
 
 int h(const string& s)
 {
+    int N = s.size();
     long long ans = 0, p = 31, q = 1'000'000'007;
 
-    for (auto c : s)
+    for (int i = N - 1; i >= 0; --i)
     {
         ans = (ans * p) % q;
         ans = (ans + f(c)) % q;
diff --git a/Strings/slides/hashes/codes/subs.cpp b/Strings/slides/hashes/codes/subs.cpp
index 0f5fed87..7a78528a 100644
--- a/Strings/slides/hashes/codes/subs.cpp
+++ b/Strings/slides/hashes/codes/subs.cpp
@@ -11,9 +11,10 @@ int f(char c)
 
 int h(const string& s)
 {
+    int N = s.size();
     ll ans = 0;
 
-    for (auto c : s)
+    for (int i = N - 1; i >= 0; --i)
     {
         ans = (ans * p) % q;
         ans = (ans + f(c)) % q;
@@ -72,8 +73,8 @@ int h(int i, int j, const vector<ll>& ps, const vector<ll>& is)
 
 int unique_substrings(const string& s)
 {
-    set<ll> hs;
     int N = s.size();
+    set<ll> hs;
 
     auto ps = prefixes(s);
     auto is = inverses(s.size());

From 03113e8daf098180ead142b3233c47dba860f86c Mon Sep 17 00:00:00 2001
From: yogi <yogiqhz@gmail.com>
Date: Mon, 16 Dec 2024 15:13:05 -0300
Subject: [PATCH 2/2] =?UTF-8?q?Corre=C3=A7=C3=A3o:=20com=20a=20mudan=C3=A7?=
 =?UTF-8?q?a=20do=20for=20precisava=20arrumar=20a=20vari=C3=A1vel=20tamb?=
 =?UTF-8?q?=C3=A9m?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 Strings/slides/hashes/codes/double_hash.cpp | 2 +-
 Strings/slides/hashes/codes/h.cpp           | 2 +-
 Strings/slides/hashes/codes/subs.cpp        | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/Strings/slides/hashes/codes/double_hash.cpp b/Strings/slides/hashes/codes/double_hash.cpp
index 5ea2fbf3..e7d890c0 100644
--- a/Strings/slides/hashes/codes/double_hash.cpp
+++ b/Strings/slides/hashes/codes/double_hash.cpp
@@ -12,7 +12,7 @@ int hi(long long pi, long long qi, const string& s)
     for (int i = N - 1; i >= 0; --i)
     {
         ans = (ans * pi) % qi;
-        ans = (ans + f(c)) % qi;
+        ans = (ans + f(s[i])) % qi;
     }
 
     return ans;
diff --git a/Strings/slides/hashes/codes/h.cpp b/Strings/slides/hashes/codes/h.cpp
index 4fec5960..04f25e11 100644
--- a/Strings/slides/hashes/codes/h.cpp
+++ b/Strings/slides/hashes/codes/h.cpp
@@ -11,7 +11,7 @@ int h(const string& s)
     for (int i = N - 1; i >= 0; --i)
     {
         ans = (ans * p) % q;
-        ans = (ans + f(c)) % q;
+        ans = (ans + f(s[i])) % q;
     }
 
     return ans;
diff --git a/Strings/slides/hashes/codes/subs.cpp b/Strings/slides/hashes/codes/subs.cpp
index 7a78528a..f97f70a7 100644
--- a/Strings/slides/hashes/codes/subs.cpp
+++ b/Strings/slides/hashes/codes/subs.cpp
@@ -17,7 +17,7 @@ int h(const string& s)
     for (int i = N - 1; i >= 0; --i)
     {
         ans = (ans * p) % q;
-        ans = (ans + f(c)) % q;
+        ans = (ans + f(s[i])) % q;
     }
 
     return ans;